TEHRAN (Press Shia Agency) – Iraq’s Popular Mobilization Units (PMU), also known as Hashd al-Shaabi, said it has collected fragments of missiles used in an airstrike against its fighters last week, which proves it was a US attack.

The paramilitary group has said it lost 22 fighters following the night raid on June 17 on the Syrian village of al-Hari in Deir Ez-zor province.

An unnamed US official, quoted by Agence France-Presse, said last Monday that Washington suspected Israel was behind the air raid but both the Syrian government and Iraqi officials have said US aircraft carried out the strike.

Hashd deputy commander Abu Mahdi al-Muhandis issued a warning to the US on Sunday, saying the fighters will not remain silent toward the targeting of their forces.

“We tell the Americans that we as the Hashd, including all of its formations, follow the Iraqi government. We will not remain silent about this attack,” Muhandis said in a statement, Press TV reported.

Hashd, now officially part of the Iraqi defense apparatus, has demanded clarification from the US, saying such strikes have occurred repeatedly during the war against terrorism.

Muhandis said the fighters had formed a committee to further investigate the strike. He called on all political parties, the government, and the parliament to “take a stance towards their sons falling martyrs.”

“Remaining silent on this incident, saying that 'that position is outside the Iraqi territory, hence we have nothing to do with it' is forfeiting the blood of our martyrs,” Muhandis added.

The popular forces were key to a three-year-long Iraqi struggle which ousted Daesh from the Arab country.

Muhandis also said US forces maintain a presence in Sinjar, using the Iraqi border town to control eastern Syria with the help of Kurdish militants.

Hashd fighters operate in the area at the request of the Syrian government to counter Daesh terrorists and keep them away from the Iraqi borders.

A de-escalation line between the US and Russia has largely prevented run-ins between pro-Damascus forces and those supported by the US, though there have been occasional clashes between them – last in April which left casualties on both sides.

The United States has in the past attacked government forces and their allies inside Syria on several occasions.

Last April, the US launched a missile attack against Shayrat Airbase in Syria’s Homs Province, claiming that the base had been used for a chemical strike.

In April, the US, France, and Britain launched coordinated attacks on Syrian targets, using more than 100 cruise missiles. The strikes used a similar excuse.

Damascus, which has surrendered its chemical weapons stockpiles, has invariably denied launching any chemical attacks.